Within the present paper we provide the arguments that contradict Gottlieb'
s conclusions regarding the theoretical implications of kinematics of movem
ents performed with unexpectedly changed inertial loads. First, the load as
sociated changes in movement velocity presented by Gottlieb may be caused b
y apparent methodological differences, when compared to our earlier results
. Moreover, the present data can be interpreted by the equilibrium-point hy
pothesis as well as by Gottlieb's hypothesis. Second, Gottlieb remains sile
nt on findings related to the movement time and symmetry ratio that contrad
ict predictions based on either torque control or Gottlieb's hypothesis. Th
erefore, we conclude that the data obtained on rapid movements performed wi
th unexpected changes in inertial load support equilibrium-point hypothesis
. rather that any of the torque control based models. (C) 2000 Elsevier Sci
ence B.V. All rights reserved.